Apparatus, System, and Method for Filamentary Composite Lattice Structure Manufacturing

ABSTRACT

An apparatus, system, and method are disclosed for the manufacture of composite lattice structures comprising a weaving mechanism  104  configured to position fibers in a lattice structure, the weaving mechanism  104  comprising one or more bobbins  304 , each one or more bobbin  304  configured to carry fiber and a plurality of horn gears  302  configured to move the one or more bobbins  304  across the face of the weaving mechanism  104  to control the position of the fiber carried by the one or more bobbins  304  in the lattice structure, and a shape retention structure  108  configured to hold the fibers in lattice structure. Beneficially, such an apparatus, system, and method would automate the process of manufacturing composite lattice structures and reduce the costs associated with the existing methods for manufacturing such structures.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 60/708,558 entitled “Apparatus, System, and Method forFilament Wound Lattice Structure Manufacturing” and filed on Aug. 16,2005 for David W. Jensen, et al., and PCT Application NumberPCT/US2006/031903 entitled “Apparatus, System, and Method for FilamentWound Lattice Structure Manufacturing” for David W. Jensen, et al.,which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the manufacture of filamentary compositelattice structures and more particularly relates to the automatedmanufacture of filamentary composite lattice structures using a weavingcomponent, a shape definition component, and a curing component.

2. Description of the Related Art

The pursuit of structurally efficient structures in the civil,mechanical, and aerospace arenas is an ongoing quest. An efficient trussstructure is one that has a high strength to weight ratio and/or a highstiffness to weight ratio. An efficient truss structure can also bedescribed as one that is relatively inexpensive, easy to fabricate andassemble, and does not waste material.

Advanced composite structures have been used in many types ofapplications to create structurally efficient structures. Some of thesecomposite structures have been used to create structural members havingenhanced load bearing capacity per unit mass and capable of withstandingmultiple loadings. An example of these composite structures is afilament composite structure with multiple, straight members attached ina lattice structure, such as the IsoTruss.

These filamentary composite lattice structures can provide excellentweight to performance ratios in multi-planar bending, buckling, axialloading, and combined loading and torsion applications, and aretherefore very valuable. The manufacture of these structures usingexisting methods, however, is labor-intensive, time consuming, andcostly.

From the foregoing discussion, it should be apparent that a need existsfor an apparatus, system, and method for manufacturing a filamentarycomposite lattice structure. Beneficially, such an apparatus, system,and method would automate the process of manufacturing filamentarycomposite lattice structures and reduce the costs associated with theexisting methods for manufacturing such structures.

SUMMARY OF THE INVENTION

The present invention has been developed in response to the presentstate of the art, and in particular, in response to the problems andneeds in the art that have not yet been fully solved by currentlyavailable methods for manufacturing filamentary composite latticestructures. Accordingly, the present invention has been developed toprovide an apparatus, system, and method for manufacturing filamentarycomposite lattice structures that overcome many or all of theabove-discussed shortcomings in the art.

The apparatus to manufacture filamentary composite lattice structures isprovided with a plurality of modules configured to functionally executethe necessary steps of weaving a filamentary composite latticestructure, defining the shape of the filamentary composite latticestructure, and transitioning the filamentary composite lattice structurefrom a weaving mechanism to a shape retention structure. These modulesin the described embodiments include a weaving mechanism configured toposition fibers in a lattice structure, a shape retention structureconfigured to hold the fibers in lattice structure, and a transitiondevice configured to transfer fibers from the weaving mechanism to theshape retention structure.

In one embodiment, the apparatus further comprises a curing deviceconfigured to cure resin on the fibers held in the shape retentionstructure. In another embodiment, the apparatus further comprises aresin impregnation device configured to apply a resin to the fibers inthe filamentary composite lattice structure. In a further embodiment,the apparatus includes a pulling device configured to apply an axialforce to the filamentary composite lattice structure.

The weaving mechanism of the apparatus, in one embodiment, comprises aplurality of horn gears configured to move a bobbin carrying fiberacross the face of the weaving mechanism. In a further embodiment, oneor more of the plurality of horn gears are driven by a spur gear on anadjacent one or more of the plurality of horn gears such that a motorattached to one of the plurality of horn gears drives the plurality ofhorn gears. In another embodiment, one or more of the plurality of horngears are driven by an individual motor.

The weaving mechanism of the apparatus, in one embodiment, furthercomprises one or more switches configured to transfer the bobbin fromone of the plurality of horn gears to an adjacent one of the pluralityof horn gears. In another embodiment, one or more of the plurality ofhorn gears further comprise an aperture configured to allow a fiber topass through the aperture. In yet another embodiment, one or more of theplurality of horn gears further comprises a gear assembly configured tobe individually removed from the weaving mechanism.

A system of the present invention is also presented to manufacturefilamentary composite lattice structures. The system may be embodied aweaving mechanism, a shape retention structure, and a control module. Inparticular, the system, in one embodiment, includes a weaving mechanismconfigured to position fibers in a lattice structure, a shape retentionstructure configured to hold the fibers in a lattice structure using oneor more attachment mechanisms, and a control module configured tocontrol the weaving mechanism and direct the positioning of the fibersin the lattice structure.

The one or more attachment mechanisms in the system, in one embodiment,may further include one or more hooks configured to hold the latticestructure in a desired configuration. In another embodiment, the one ormore attachment mechanisms include one or more servo mechanismsconfigured to hold the lattice structure in a desired configuration.

In one embodiment, the relative position of the one or more attachmentmechanisms is variable such that a bay length in a filamentary compositelattice structure manufactured by the system is adjustable. In anotherembodiment, the relative position of the one or more attachmentmechanisms is variable such that a diameter of a filamentary compositelattice structure manufactured by the system is adjustable.

The system, in one embodiment, includes the one or more attachmentmechanisms that move relative to the weaving mechanism as the systemmanufactures a filamentary composite lattice structure such that thefilamentary composite lattice structure is continuously manufactured. Inanother embodiment, the shape retention structure is curved such thatthe filamentary composite lattice produced by the system is curved.

A method of the present invention is also presented for manufacturing afilamentary composite lattice structure. The method in the disclosedembodiments substantially includes the steps necessary to carry out thefunctions presented above with respect to the operation of the describedapparatus and system. In one embodiment, the method includes positioningfibers to form a lattice structure with a weaving mechanism,transitioning fibers in assembled lattice structure to a shape retentionstructure, and constraining the geometry of the assembled latticestructure in the shape definition component.

In a further embodiment, the method includes curing resin in theassembled lattice structure. The method may include, in anotherembodiment, tensioning the fibers with a pulling device.

Reference throughout this specification to features, advantages, orsimilar language does not imply that all of the features and advantagesthat may be realized with the present invention should be or are in anysingle embodiment of the invention. Rather, language referring to thefeatures and advantages is understood to mean that a specific feature,advantage, or characteristic described in connection with an embodimentis included in at least one embodiment of the present invention. Thus,discussion of the features and advantages, and similar language,throughout this specification may, but do not necessarily, refer to thesame embodiment.

Furthermore, the described features, advantages, and characteristics ofthe invention may be combined in any suitable manner in one or moreembodiments. One skilled in the relevant art will recognize that theinvention may be practiced without one or more of the specific featuresor advantages of a particular embodiment. In other instances, additionalfeatures and advantages may be recognized in certain embodiments thatmay not be present in all embodiments of the invention.

These features and advantages of the present invention will become morefully apparent from the following description and appended claims, ormay be learned by the practice of the invention as set forthhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the advantages of the invention will be readilyunderstood, a more particular description of the invention brieflydescribed above will be rendered by reference to specific embodimentsthat are illustrated in the appended drawings.

Understanding that these drawings depict only typical embodiments of theinvention and are not therefore to be considered to be limiting of itsscope, the invention will be described and explained with additionalspecificity and detail through the use of the accompanying drawings, inwhich:

FIG. 1 is a schematic block diagram illustrating one embodiment of asystem for manufacturing a filamentary composite lattice structure inaccordance with the present invention;

FIG. 2 is a side view illustrating one embodiment of an apparatus tomanufacture a filamentary composite lattice structure in accordance withthe present invention;

FIG. 3 is a front view illustrating one embodiment of a weavingmechanism apparatus in accordance with the present invention;

FIG. 4 is a front view illustrating one embodiment of a weavingmechanism apparatus in accordance with the present invention;

FIG. 5 is a cut away side view illustrating one embodiment of a gearassembly apparatus in accordance with the present invention;

FIG. 6 is a side view illustrating one embodiment of a bobbin carrierapparatus in accordance with the present invention;

FIG. 7 is a side view illustrating one embodiment of a shape retentionstructure apparatus in accordance with the present invention;

FIG. 8 is a side view illustrating one embodiment of a transition deviceapparatus in accordance with the present invention; and

FIG. 9 is a schematic flow chart diagram illustrating one embodiment ofa filamentary composite lattice structure manufacturing method inaccordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Many of the functional units described in this specification have beenlabeled as modules, in order to more particularly emphasize theirimplementation independence. For example, a module may be implemented asan assembly of one or more mechanical components, a hardware circuitcomprising custom VLSI circuits or gate arrays, off-the-shelfsemiconductors such as logic chips, transistors, or other discretecomponents. A module may also be implemented in programmable hardwaredevices such as field programmable gate arrays, programmable arraylogic, programmable logic devices or the like.

Modules may also be implemented in software for execution by varioustypes of processors. An identified module of executable code may, forinstance, comprise one or more physical or logical blocks of computerinstructions which may, for instance, be organized as an object,procedure, or function. Nevertheless, the executables of an identifiedmodule need not be physically located together, but may comprisedisparate instructions stored in different locations which, when joinedlogically together, comprise the module and achieve the stated purposefor the module.

Indeed, a module of executable code may be a single instruction, or manyinstructions, and may even be distributed over several different codesegments, among different programs, and across several memory devices.Similarly, operational data may be identified and illustrated hereinwithin modules, and may be embodied in any suitable form and organizedwithin any suitable type of data structure. The operational data may becollected as a single data set, or may be distributed over differentlocations including over different storage devices, and may exist, atleast partially, merely as electronic signals on a system or network.

Reference throughout this specification to “one embodiment,” “anembodiment,” or similar language means that a particular feature,structure, or characteristic described in connection with the embodimentis included in at least one embodiment of the present invention. Thus,appearances of the phrases “in one embodiment,” “in an embodiment,” andsimilar language throughout this specification may, but do notnecessarily, all refer to the same embodiment.

Reference to a signal bearing medium may take any form capable ofgenerating a signal, causing a signal to be generated, or causingexecution of a program of machine-readable instructions on a digitalprocessing apparatus. A signal bearing medium may be embodied by atransmission line, a compact disk, digital-video disk, a magnetic tape,a Bernoulli drive, a magnetic disk, a punch card, flash memory,integrated circuits, or other digital processing apparatus memorydevice.

Furthermore, the described features, structures, or characteristics ofthe invention may be combined in any suitable manner in one or moreembodiments. In the following description, numerous specific details areprovided, such as examples of programming, software modules, userselections, network transactions, database queries, database structures,hardware modules, hardware circuits, hardware chips, etc., to provide athorough understanding of embodiments of the invention. One skilled inthe relevant art will recognize, however, that the invention may bepracticed without one or more of the specific details, or with othermethods, components, materials, and so forth. In other instances,well-known structures, materials, or operations are not shown ordescribed in detail to avoid obscuring aspects of the invention.

Some basic features of the manufacture of a complex composite structureare described in U.S. Pat. Publication No. US2004/0247866A1, publishedDec. 9, 2004, which is herein incorporated by reference into thisdocument.

FIG. 1 illustrates a system 100 for manufacturing a lattice structure.The system 100, in one embodiment, may comprise a lattice structuremanufacturing device 102, a weaving mechanism 104, a transition device106, a shape retention structure 108, a resin impregnation device 110, acuring device 112, a pulling device 114, and a control module 116. Thesystem 100 manufactures a lattice structure from fibers.

The lattice structure manufacturing device 102, in one embodimentcomprises a weaving mechanism 104, a transition device 106, a shaperetention structure 108, a resin impregnation device 110, a curingdevice 112, and a pulling device 114. The weaving mechanism 104 directsthe relative position of a plurality of fibers that make up the latticestructure. In one embodiment, the weaving mechanism 104 may weave aplurality of fibers. In another embodiment, the weaving mechanism 104may braid a plurality of fibers. In yet another embodiment, the weavingmechanism 104 may wrap one or more fibers around one or more fibers.

As will be appreciated by one skilled in the art, a variety ofconfigurations of the weaving mechanism 104 should be considered to fallwithin the scope of the invention. For example, in one embodiment, theweaving mechanism 104 may interweave fibers at the joints of a latticestructure that may be stronger and more durable than non-interwovenjoints. In another embodiment, the weaving mechanism 104 may wrap fibersaround the straight elements of the lattice structure to aid inconsolidation of fibers. In yet another embodiment, the weavingmechanism 104 may be capable of arranging fibers into multiple latticeconfigurations, such as IsoTrusses, rectangular lattice structuretrusses, flat lattice structure panels, and the like.

In one embodiment, the transition device 106 guides fibers from theweaving mechanism 104 onto the shape retention structure 108. Thetransition device 106 may comprise hooks, clasps, guides, or the like.The transition device 106 acts to ensure proper transition of the fibersinto a correct geometry.

The shape retention structure 108, in one embodiment, receives fibersfrom the transition device 106 and holds the fibers in the proper shapefor the lattice structure. The shape retention structure 108 constrainsthe geometry of the lattice structure and maintains the geometry duringcuring of the structure. The shape retention structure 108 may beconfigured to operate continuously as a lattice structure is formed,releasing portions of the structure that have been cured, and acceptingadditional uncured portions of the lattice structure from the transitiondevice 106. In one embodiment, the shape retention structure 108 maycomprise hooks, clasps, grips, or the like that are held in a frame andattach to the lattice structure.

One skilled in the art will recognize that a variety of configurationsof shape retention structure 108 should be considered to be within thescope of the invention. For example, in one embodiment, the shaperetention structure 108 may comprise a mandrel. In another embodiment,the shape retention structure 108 may include an integral transitiondevice 106. In another embodiment, the shape retention structure 108 maycomprise robotic arms that constrain the geometry of the latticestructure. In yet another embodiment, the shape retention structure 108may comprise a frame that has a variable geometry such that the latticestructure can be curved.

The resin impregnation device 110 applies resin to the fibers in thelattice structure. The resin is later cured and acts as a matrix to holdthe fibers in position. In one embodiment, the resin impregnation device110 sprays resin onto fibers held in the shape retention structure 108.

In another embodiment, the resin impregnation device 110 applies resinto fibers in the weaving mechanism 104. In yet another embodiment, theresin impregnation device applies resin to fibers in the transitiondevice 106. In another embodiment, the fibers are pre-impregnated withresin (pre-preg) and the resin impregnation device 110 is not included.

The curing device 112, in one embodiment, cures the resin in the latticestructure held by the shape retention structure 108. The curing device112 may continuously cure the resin in the lattice structure as thelattice structure is assembled. In one embodiment, the curing device 112may comprise a heat curing apparatus.

As will be appreciated by one skilled in the art, a variety of types andconfigurations of curing device 112 may be implemented without departingfrom the scope and spirit of the present invention. For example, in oneembodiment, the curing device 112 may use a microwave curing apparatus.In another embodiment, the curing device 112 may use an ultravioletlight (UV) curing apparatus. In yet another embodiment, the curingdevice 112 may completely cure the resin in the lattice structure. Inanother embodiment, the curing device 112 may cure the outer layer ofthe lattice structure to maintain the geometry of the structure.

The pulling device 114, in one embodiment, applies an axial force to thelattice structure. The axial force may be translated through the latticestructure to the fibers in the weaving mechanism 104. The axial forcegenerated by the pulling device 114 pulls the lattice structure from thelattice structure manufacturing device 102 as the structure isprogressively assembled, and maintains the correct tension in the fibersas the lattice structure is assembled. In one embodiment, the pullingdevice 114 comprises a motorized winch with a cable attached to thelattice structure.

One skilled in the art will appreciate that a variety of types andconfigurations of pulling device 112 may be implemented withoutdeparting from the scope and spirit of the invention. For example, inone embodiment, the pulling device 112 comprises a weight attached to acable attached to the lattice structure. In another embodiment, thepulling device 112 comprises tension applied by the shape retentionstructure 108 applied to the lattice structure.

The control module 116, in one embodiment, provides control over thevarious components of the lattice structure manufacturing device 102.The control module 116 may comprise a computing device configured withinsoftware code to control the movement and actions of the weavingmechanism 104, the transition device 106, the shape retention structure108, the resin impregnation device 110, the curing device 112, and/orthe pulling device 114. In one embodiment, the control module 116 may beconfigured to allow a user to select or design the geometry of a latticestructure, adjust the components of the lattice structure manufacturingdevice 102 to create that structure, and control the action of thecomponents of the lattice structure manufacturing device 102 as thedesired structure is created.

FIG. 2 illustrates one embodiment of a side view of an apparatus 200 tomanufacture a filamentary composite lattice structure. The apparatus 200may comprise a weaving mechanism 104, a transition device 106, a shaperetention structure 108, a curing device 112, and a pulling device 114.Also illustrated are a plurality of fibers 202 and a lattice structure204. The apparatus 200 manufactures a lattice structure from fibers. Theweaving mechanism 104, the transition device 106, the shape retentionstructure 108, the curing device 112, and the pulling device 114 aresimilar in function to like numbered elements discussed above inrelation to FIG. 1.

The plurality of fibers 202, in one embodiment, comprises fibers thatare formed by the apparatus 200 into a lattice structure. The fibers 202may be any fiber used to make composite structures, such as carbon,aramid, fiberglass, or the like. In one embodiment, the fibers 202 areimpregnated with resin before entering the apparatus 200. In anotherembodiment, the fibers 202 are not impregnated with resin beforeentering the apparatus 200.

The lattice structure 204 is formed from the plurality of fibers 202 bythe apparatus 200. In one embodiment, the lattice structure 204 may bean IsoTruss structure. In another embodiment, the lattice structure 204may be a lattice structure truss with a rectangular cross-section. Inyet another embodiment, the lattice structure 204 may be a flat latticestructure panel. In another embodiment, the lattice structure 204 may bea curved lattice structure. In another embodiment, the lattice structure204 may be a tapered lattice structure.

FIG. 3 illustrates a front view of one embodiment of a weaving mechanism300. The weaving mechanism 300 comprises a plurality of horn gears 302,and one or more bobbin carriers 304. The weaving mechanism 300transports the one or more bobbin carriers 304 on a path across the faceof the weaving mechanism 300 to position fibers in a lattice structure.

As will be appreciated by one skilled in the art, variations of theweaving mechanism 300 that comprise any number of horn gears 302 and arearranged in any shape should be considered to be within the scope andspirit of the invention. FIG. 1 illustrates a weaving mechanism 300containing 16 horn gears 302 arranged in a square panel. In anotherembodiment, the weaving mechanism 300 may contain hundreds of horn gears302. In another embodiment, the horn gears 302 may be arranged in acircle across the face of the weaving mechanism 300.

The plurality of horn gears 302, in one embodiment, each comprises oneor more notches 306, an aperture 308, and an axis of rotation 310. Eachhorn gear 302 rotates around its axis of rotation 310 and may carry abobbin carrier 304 in a notch 306. A horn gear 302 may transfer a bobbincarrier 304 to an adjacent horn gear 302. Transfer of a bobbin carrier304 may occur in response to both horn gears 302 having aligned notches306 and the direction of a switch (not shown). Through these transfers,a bobbin carrier 304 may follow a path across the surface of the weavingmechanism 300.

The plurality of horn gears 302 may be gear driven such that each horngear 302 rotates at the same rate as each adjacent horn gear 302, but inthe opposite direction. In another embodiment, the rotation of each horngear 302 is independently controlled. The plurality of horn gears 302may be driven by one or more motors.

The plurality of horn gears 302 may each include an aperture 308 at theaxis of rotation 310. One or more fibers may pass through the aperture308 and be incorporated into the lattice structure. In one embodiment,the fibers that pass through an aperture 308 form the longitudinalmembers of the lattice structure. The fibers that pass through an ataperture 308 may be drawn through the aperture 308 by the progression ofthe lattice structure.

The one or more bobbin carriers 304, in one embodiment, may each carry abobbin of fiber as they traverse the weaving mechanism 300. Fiber may bedrawn from the bobbins and arranged into a lattice structure by themotion of the bobbin carriers 304 and the progression of the latticestructure. As the bobbin carriers 304 move across the weaving mechanism300, fibers may be braided, woven, and/or wrapped around one another.

FIG. 4 illustrates a front view of one embodiment of a weaving mechanism400. The weaving mechanism 400 comprises a plurality of horn gears 302,one or more bobbin carriers 304, and one or more switches 402. Theweaving mechanism 400 transports the one or more bobbin carriers 304 ona path across the face of the weaving mechanism 400 to position fibersin a lattice structure.

In one embodiment, the plurality of horn gears 302 and the one or morebobbin carriers 304 are preferably configured in a manner similar tolike numbered components described above in relation to FIG. 3. The oneor more switches 402 direct the transfer of the bobbin carriers 304between horn gears 302. In one embodiment, the switches 402 are locatedat the interface between horn gears 302.

In one embodiment, the one or more switches 402 comprise avariable-geometry guide that switches between a transfer state and acontinue state. A bobbin carrier 304 traversing a switch 402 in thetransfer state is transferred to the adjacent horn gear 302. A bobbincarrier 304 traversing a switch 402 in the continue state continues totravel on its current horn gear 302.

The one or more switches 402 may be switched between a transfer stateand a continue state by a solenoid. In another embodiment, the one ormore switches 402 may be switched by a motor. In another embodiment, theone or more switches 402 may be switched pneumatically.

FIG. 5 illustrates a side view cross section of one embodiment of a gearassembly 500. The gear assembly 500 comprises a horn gear 302, a weavingmechanism surface 502, an axle 504, and a drive gear 506. The gearassembly 500 controls the rotation of the horn gear 302 in a weavingmechanism.

In one embodiment, the horn gear 302 includes an aperture 308 and anaxis of rotation 310. The horn gear 302, aperture 308 and axis ofrotation 310 are preferably configured in a manner similar to likenumbered components described above in relation to FIG. 3. The horn gear302 rotates around the axis of rotation 310 and may carry one or morebobbin carriers 304 across the weaving mechanism 300.

The weaving mechanism surface 502, in one embodiment, provides a surfacefor the bobbin carrier to slide. In one embodiment, the weavingmechanism surface 502 is sectioned such that each gear assembly 500 maybe removed from the weaving mechanism for maintenance and repair. Thegear assembly 500 may slide toward the horn gear 302 for removal. Inanother embodiment, the gear assembly 500 may slide toward the drivegear 506 for removal. In yet another embodiment, the segmented weavingmechanism surface 502 may be removably attached to adjacent weavingmechanism surfaces 502 by a fastener.

The axle 504, in one embodiment, may be attached to the horn gear 302and share a common axis of rotation 310 with the horn gear 302. The axle504 translates motion from the drive gear 506 to the horn gear 302. Inanother embodiment, the axle 504 is hollow and provides an aperture 308.Fiber used to form a lattice structure may pass through the aperture308. The axle 504 may be made from any material strong and stiff enoughto transfer force from the drive gear 506 to the horn gear 302, such assteel, aluminum, alloys, plastic, composites, or the like.

The drive gear 506, in one embodiment, may be attached to the axle 504and share a common axis of rotation with the axle 504 and the horn gear302. The drive gear 506 may be a spur gear that meshes with adjacentdrive gears 506 in adjacent gear assemblies 500. The drive gear 506 maybe driven by an adjacent drive gear 506. The drive gear 506 may drive anadjacent drive gear 506. The drive gear 506 transfers rotational motionto the axle 504 to drive the horn gear 302. The drive gear 506 may bemade from any material sufficiently strong, stiff, and durable enough totransfer rotational motion, such as steel, aluminum, alloys, plastic,composites, or the like.

As will be appreciated by one skilled in the art, a variety ofconfigurations of drive gear 506 may be employed without departing fromthe scope or spirit of the invention. For example, in one embodiment,the drive gear 506 may be independently driven by a motor. In anotherembodiment, the drive gear 506 may be driven by a belt.

FIG. 6 illustrates one embodiment of a side view of a bobbin carrier600. The bobbin carrier 600 comprises a bobbin 602, a horn gearinterface 604, and a track guide 606. The bobbin carrier 600 istransported by a horn gear 302 across a weaving mechanism surface 502and carries a bobbin of fiber as fiber is drawn from the bobbin 602 tomake a lattice structure.

In one embodiment, the bobbin 602 is wrapped with a single strand offiber that is drawn from the bobbin 402. The bobbin 602 may be removablefrom the bobbin carrier 600. In another embodiment, the bobbin 602 isintegral with the bobbin carrier 600. In another embodiment, the bobbin602 carries more than one strand of fiber.

The horn gear interface 604, in one embodiment, has a shape that matchesthe notches on a horn gear 302 in a weaving mechanism. The horn gearinterface 604 allows the bobbin carrier 300 to securely rest in arotating horn gear 302 as the bobbin carrier 300 moves. In oneembodiment, the horn gear interface 604 may have a circular crosssection, allowing for any rotational orientation within a notch of ahorn gear 302. In another embodiment, the horn gear interface 604 mayhave a shaped cross section, allowing specific rotational orientationswithin a notch of a horn gear 302.

The track guide 606, in one embodiment, interfaces with a track on theweaving mechanism surface 502 and guides the motion of the bobbincarrier 600. The track guide 606 may interact with a switch to controltransfer of the bobbin carrier between horn gears.

FIG. 7 illustrates one embodiment of a shape retention structure 700.The shape retention structure 700 comprises a frame 702 and one or moreattachment mechanisms 704. The shape retention structure 700 constrainsthe geometry of a curing lattice structure 706.

In one embodiment, the frame 702 may provide a base for the one or moreattachment mechanisms 704. The frame 702 may remain stationary as thelattice structure 706 is assembled and allow the one or more attachmentmechanisms 704 to travel with the lattice structure 706. In an alternateembodiment, the frame 702 may travel with the lattice structure 706 asit is assembled. In one embodiment, the frame 702 may comprise one ormore rails arranged around the lattice structure 706.

As will be appreciated by one skilled in the art, a variety of types andconfigurations of frame 702 may be implemented without departing fromthe scope or spirit of the invention. For example, in one embodiment,the frame 702 may comprise one or more rings that encircle the latticestructure 706. In another embodiment, the frame 702 may comprise one ormore tracks arranged around the lattice structure 706. In anotherembodiment, the frame 702 may comprise a base on which actuators forcontrolling the one or more attachment mechanisms 704 are mounted.

In one embodiment, the frame 702 is adjustable such that a diameter 708of the lattice structure 706 may be varied. In another embodiment, theframe 702 is adjustable such that a bay length 710 of the latticestructure 706 may be varied. In another embodiment, the diameter 708and/or bay length 710 may be varied during the process of assembling alattice structure 706.

In another embodiment, the frame 702 may be adjustable such that thelattice structure 706 may be held in a bent or curved position. Theframe 702 may, in another embodiment, be configured to hold a latticestructure 706 in an iso-truss configuration. In another embodiment, theframe 702 may be configured to hold a lattice structure 706 in a flatpanel configuration. In another embodiment, the frame 702 may beconfigured to hold a lattice structure 706 in a rectangularcross-section configuration.

The one or more attachment mechanisms 704 attach to the latticestructure 706 and constrain the geometry of the lattice structure 706.The lattice structure 706 is held in shape during curing. In oneembodiment, the one or more attachment mechanisms 704 are hooksconnected to the frame 702.

As will be appreciated by one skilled in the art, a variety of types andconfigurations of one or more attachment mechanisms 704 may be employedwithout departing from the scope and spirit of the invention. Forexample, in one embodiment, the one or more attachment mechanisms 704may comprise a grip mechanism. In another embodiment, the one or moreattachment mechanisms 704 may comprise a variable geometry mechanismthat allows the constraint and release of the lattice structure 706. Inanother embodiment, the one or more attachment mechanisms 704 maycomprise one or more robotic arms with controllable servo mechanisms.

In another embodiment, the one or more attachment mechanisms 704 may beadjustable such that the diameter 708 of the lattice structure 706 maybe varied. In another embodiment, the one or more attachment mechanisms704 may be adjustable such that the bay length 710 of the latticestructure 706 may be varied. In another embodiment, the diameter 708and/or bay length 710 may be varied during the process of assembling alattice structure 706.

In one embodiment, the shape retention structure 700 may act as apulling device. The shape retention structure 700 may provide tension inthe fibers for the manufacturing process. The shape retention structure700 may also draw fiber from bobbins and move the lattice structure 706away from the weaving mechanism as the lattice structure 706 isassembled.

FIG. 8 illustrates one embodiment of a side view of a transition device800. The transition device 800 comprises one or more transition wheels802. The transition device 800 guides fibers from the weaving mechanism104 to onto the shape retention structure 108.

The one or more transition wheels 802 may each include a hub 804 and oneor more hooks 806. The hub 802, in one embodiment, rotates and providesan attachment for the one or more hooks 806. The one or more hooks 806,in one embodiment, engage fibers from the weaving mechanism 104 as thehub 804 rotates. The one or more hooks 806 may carry the fiber in apredetermined orientation to the shape retention structure 108. In oneembodiment, the one or more hooks 806 may release the fibers in responseto the engagement of the shape retention structure 108 with the fibers.

As will be appreciated by one skilled in the art, a variety of types andconfigurations of transition devices 800 may be utilized withoutdeparting from the scope and spirit of the present invention. Forexample, the transition device 800, in one embodiment, may comprise oneor more servo-driven actuators configured to engage fibers and deliverthem to the shape retention structure 108. In another embodiment, thetransition device 800 may include a four-bar linkage configured to carrythe fibers on a pre-determined path from the weaving mechanism 104 tothe shape retention structure 108.

The schematic flow chart diagrams that follow are generally set forth aslogical flow chart diagrams. As such, the depicted order and labeledsteps are indicative of one embodiment of the presented method. Othersteps and methods may be conceived that are equivalent in function,logic, or effect to one or more steps, or portions thereof, of theillustrated method. Additionally, the format and symbols employed areprovided to explain the logical steps of the method and are understoodnot to limit the scope of the method. Although various arrow types andline types may be employed in the flow chart diagrams, they areunderstood not to limit the scope of the corresponding method. Indeed,some arrows or other connectors may be used to indicate only the logicalflow of the method. For instance, an arrow may indicate a waiting ormonitoring period of unspecified duration between enumerated steps ofthe depicted method. Additionally, the order in which a particularmethod occurs may or may not strictly adhere to the order of thecorresponding steps shown.

FIG. 9 illustrates a method 900 for manufacturing a lattice structure.Initially, fiber tows are arranged 902 in the manufacturing apparatus.In selected embodiments, fibers may be threaded through an aperture 308in a horn gear 302, or be placed on a bobbin 602 on a bobbin carrier304. The desired arrangement of the fibers may be determined by thelattice structure to be created.

Next, the fibers are attached 904 to the pulling device. The fibers maybe tied to the pulling device. In another embodiment, fibers areattached to the pulling device by fasteners.

Next, the fibers are tensioned 906 by the pulling device. The tensionapplied by the pulling device holds the fibers in position. The tensionmay also draw fibers through the apparatus. In another embodiment, thetension draws the assembled lattice structure through the apparatus.

Next, the fibers are positioned 908 by the weaving mechanism. Fibers maybe arranged side by side, wrapped around other fibers, woven together,and/or braided together by the weaving mechanism. The positioning of thefibers may be controlled by the weaving mechanism to arrange the fibersin the desired configuration to form a lattice structure.

Next, the assembled lattice structure is transitioned 910 onto a shaperetention structure. The lattice structure may be placed on guidesand/or attachment mechanisms 704.

Next, the geometry of the lattice structure is constrained 912 by theshape retention structure. The shape retention structure holds thelattice structure in the desired shape and configuration while thestructure is flexible. The shape retention structure may also tensionthe fibers.

Next, the resin in the lattice structure is cured 914. The flexiblestructure held in the shape retention structure is made rigid by thecuring process. The resin may be cured by a heat process, a microwaveprocess, an ultraviolet process, or the like. In one embodiment, theresin may be fully cured in the shape retention structure. In anotherembodiment, the resin may be partially cured in the shape retentionstructure.

Next, the lattice structure is released 916 from the shape retentionstructure. The structure may be released through the action of one ormore variable geometry attachment mechanisms 704. In another embodiment,the structure may be released releasing tension on one or moreattachment mechanisms 704.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. An apparatus to manufacture filamentary composite lattice structures,the apparatus comprising: a weaving mechanism configured to positionfibers in a lattice structure, the weaving mechanism comprising: one ormore bobbins, each one or more bobbin configured to carry fiber; and aplurality of horn gears configured to move the one or more bobbinsacross the face of the weaving mechanism to control the position of thefiber carried by the one or more bobbins in the lattice structure; and ashape retention structure configured to hold the fibers in latticestructure until the lattice structure is cured to a rigid state.
 2. Theapparatus of claim 1, further comprising a curing device configured tocure resin on the fibers held in the shape retention structure.
 3. Theapparatus of claim 1, further comprising a resin impregnation deviceconfigured to apply a resin to the fibers in the filamentary compositelattice structure.
 4. The apparatus of claim 1, further comprising apulling device configured to apply an axial force to the filamentarycomposite lattice structure.
 5. The apparatus of claim 1 wherein one ormore of the plurality of horn gears are driven by a spur gear on anadjacent one or more of the plurality of horn gears such that a motorattached to one of the plurality of horn gears drives the plurality ofhorn gears.
 6. The apparatus of claim 1 wherein one or more of theplurality of horn gears are driven by an individual motor.
 7. Theapparatus of claim 1 wherein the weaving mechanism further comprises oneor more switches configured to transfer the bobbin from one of theplurality of horn gears to an adjacent one of the plurality of horngears.
 8. The apparatus of claim 1 wherein one or more of the pluralityof horn gears further comprise an aperture configured to allow a fiberto pass through the aperture.
 9. The apparatus of claim 1 wherein one ormore of the plurality of horn gears further comprises a gear assemblyconfigured to be individually removed from the weaving mechanism. 10.The apparatus of claim 1, further comprising a transition deviceconfigured to transfer fibers from the weaving mechanism to the shaperetention structure.
 11. A system to manufacture filamentary compositelattice structures, the system comprising: a weaving mechanismconfigured to position fibers in a lattice structure, the weavingmechanism comprising: one or more bobbins, each one or more bobbinconfigured to carry fiber; and a plurality of horn gears configured tomove the one or more bobbins across the face of the weaving mechanism tocontrol the position of the fiber carried by the one or more bobbins inthe lattice structure; a shape retention structure configured to holdthe fibers in a lattice structure using one or more attachmentmechanisms; and a control module configured to control the weavingmechanism and direct the positioning of the fibers in the latticestructure.
 12. The system of claim 11 wherein the one or more attachmentmechanisms comprise one or more hooks configured to hold the latticestructure in a desired configuration.
 13. The system of claim 11 whereinthe one or more attachment mechanisms comprise one or more servomechanisms configured to hold the lattice structure in a desiredconfiguration.
 14. The system of claim 11 wherein the relative positionof the one or more attachment mechanisms is variable such that a baylength in a filamentary composite lattice structure manufactured by thesystem is adjustable.
 15. The system of claim 11 wherein the relativeposition of the one or more attachment mechanisms is variable such thata diameter of a filamentary composite lattice structure manufactured bythe system is adjustable.
 16. The system of claim 11 wherein the one ormore attachment mechanisms move relative to the weaving mechanism as thesystem manufactures a filamentary composite lattice structure such thatthe filamentary composite lattice structure is continuouslymanufactured.
 17. The system of claim 11 wherein the shape retentionstructure is curved such that the filamentary composite lattice producedby the system is curved.
 18. A method for manufacturing a filamentarycomposite lattice structure, the method comprising: positioning fibersto form a lattice structure with a weaving mechanism configured toposition fibers in a lattice structure, the weaving mechanismcomprising: one or more bobbins, each one or more bobbin configured tocarry fiber; and a plurality of horn gears configured to move the one ormore bobbins across the face of the weaving mechanism to control theposition of the fiber carried by the one or more bobbins in the latticestructure; and constraining the geometry of the assembled latticestructure in the shape definition component.
 19. The method of claim 17,wherein the method further comprises curing resin in the assembledlattice structure.
 20. The method of claim 17, further comprisingtensioning the fibers with a pulling device.